A semiconductor device includes, for example, a silicide used to reduce contact resistance between a diffusion layer and a contact. The silicide is formed, for example, by annealing a metal that is embedded in a bottom of a contact hole.
In the formation of the silicide layer in this manner, if the contact hole is deep, the metal cannot be adequately embedded in the bottom of the contact hole, which may cause an incomplete silicide layer. This may increase the contact resistance.